#include <iostream>
using namespace std;

double foo(int s,int t,int p){
    double a1 = (1-p)*s+p*s; 
    double a2 = a1 / t;
    return a2;
}

int main(){
    double p,k,S,T;
    cout << "Source value : ";
    cin >> S;
    cout << "Target Value : ";
    cin >> T;
    cout << "part of optimize : ";
    cin >> p;

    k = foo(S,T,p);
    cout << "[+] optimize rate :" << k << endl;
}